In a mining site of a mine, a transporter vehicle such as a dump truck is operated, and the transporter vehicle transports cut stones or the like. The transporter vehicle travels along a traveling road provided in the mine in a loading state where cut stones or the like are loaded on the transporter vehicle or an empty state where no load exists therein. When the traveling transporter vehicle collides with an object, the transporter vehicle is damaged, and hence the operation of transporting cut stones or the like is disturbed. Thus, the productivity of the mining site is degraded. For that reason, a collision prevention device disclosed in Patent Literature 1 is used in the transporter vehicle.